Antibacterial Agents
Antibiotics Antibacterial Agents

Antibacterial Agents

Most antibacterial agents are considered compatible with lactation and are not an indication to pump and dump. In general, it is reasonable to monitor breastfed infants for gastrointestinal side effects such as diarrhea, thrush, diaper rash, or blood in the stool while their lactating parent is on an antibiotic. Only antibacterial agents with special considerations during lactation are outlined in this section. Many currently available antibiotics, such as penicillins and cephalosporins, are generally considered safe during lactation.

For more detailed information and references on specific medications, please refer to LactMede-lactanciaInfant Risk, or Mother to Baby. Please refer to any of these resources for novel antibiotic agents.


Trimethoprim-sulfamethoxazole has relatively low milk transfer compared to infant weight-based dosing (1). Additionally, no reports of jaundice related to the use of trimethoprim-sulfamethoxazole were found in a systematic review of the literature (2). However, there is a theoretical risk of jaundice among breastfed infants who are at highest risk, so caution may be warranted and alternatives should be considered in specific populations, including neonates under 8 days old, premature infants, stressed or ill infants, and jaundiced infants. This agent should be avoided in lactating parents of G6PD-deficient infants (3). While there is no absolute indication to pump and dump, shared decision making should be utilized in certain special groups of infants with risk factors for jaundice and alternative medications are preferred for lactating parents of G6PD-deficient infants.


Dapsone has limited data in lactation. It appears to readily enter breast milk. There is a case report of hemolytic anemia in a newborn likely due to exposure to dapsone through breastmilk (4). Hemolytic anemia may occur with the use of this medication, especially in  full-term or preterm newborns  and in those with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Therefore, systemic Dapsone should be used with caution in lactating parents with shared decision making and close monitoring of the infant for signs of hemolytic anemia. An alternative agent should be considered for lactating parents of G6PD-deficient infants.


Commonly used fluoroquinolones include ciprofloxacin/Cipro, levofloxacin/Levaquin, ofloxacin/Floxin/Ocuflox.

  • Systemic fluoroquinolones (ciprofloxacin/Cipro, levofloxacin/Levaquin): There is one case report of pseudomembranous colitis in an infant of a mother who self-treated with ciprofloxacin at unclear doses (5). However, levels of ciprofloxacin and levofloxacin excreted in human milk at usual maternal doses are relatively low and breastfed infant plasma levels are undetectable or very low with the use of levofloxacin (6). There is no absolute indication to pump and dump with the use of oral fluoroquinolones at prescribed doses.
  • Topical fluoroquinolone (otic ofloxacin/Floxin Otic, ophthalmic ofloxacin/Ocuflox): When used topically, exceedingly low maternal plasma levels are expected and these medications are unlikely to enter breastmilk in significant amounts. There is no absolute indication to pump and dump with topical otic or ophthalmic use.


Macrolide antibiotics include erythromycin and azithromycin/Zithromax.

  • Erythromycin: An association between certain macrolides, including erythromycin, and the incidence of pyloric stenosis has been described in a cohort study (7). There is one case report of a 3 week old, breastfed infant developing pyloric stenosis after exposure to this medication via breastmilk (8). While direct erythromycin exposure given to newborns is a risk factor for the development of pyloric stenosis, two larger recent meta-analyses have not found a link between erythromycin exposures via breastmilk and pyloric stenosis (9, 10). While erythromycin should be used with caution in lactating parents of newborns, with close monitoring for symptoms of pyloric stenosis (such as forceful vomiting), there is no absolute indication to pump and dump and providers should engage lactating individuals in shared decision making with the use of erythromycin.
  • Azithromycin/Zithromax: There are no reports of adverse events in breastfed infants per LactMed and more recent meta-analyses did not show a link between macrolide use and pyloric stenosis (9, 10). There is no absolute indication to pump and dump.


Nitrofurantoin/Macrobid use results in low levels of this medication in human milk. While there are no case reports of hemolytic anemia among breastfed infants, infants under 1 month of age and infants with G6PD deficiency are at risk of hemolysis when they are directly given nitrofurantoin. While there is no absolute indication to pump and dump, alternatives are preferred in lactating individuals with newborns or G6PD deficient infants. Breastfed infants should be monitored closely for signs of hemolytic anemia.


Tetracyclines (tetracycline, doxycycline, minocycline/Minocin, tigecycline/Tigacyl) carry a risk of dental staining and bone deposition if given directly to infants and young children. Per LactMed, available literature suggests these medications can be used in short courses (<21 days) as milk levels are low and absorption by breastfed infants is low due to the medication binding with calcium in breastmilk. Out of an abundance of caution, longer courses or repeated treatments with tetracyclines are not recommended during lactation. While there is no absolute indication to pump and dump, limit the use of tetracyclines to  less than 3 weeks and avoid repeated use.


  1. Miller RD, Salter AJ. The passage of trimethoprim/sulfamethoxazole into breast milk and its significance. In, Daikos CK, ed. Progress in Chemotherapy. Antibacterial chemotherapy 1974;1:687-91.
  2. Forna F, McConnell M, Kitabire FN, et al. Systematic review of the safety of trimethoprim-sulfamethoxazole for prophylaxis in HIV-infected pregnant women: Implications for resource-limited settings. AIDS Rev. 2006;8:24–36.
  3. Chung AM, Reed MD, Blumer JL. Antibiotics and breast-feeding: A critical review of the literature. Paediatr Drugs. 2002;4:817–37. DOI:
  4. Sanders SW, Zone JJ, Foltz RL et al. Hemolytic anemia induced by dapsone transmitted through breast milk. Ann Intern Med. 1982;96:465-6. DOI:
  5. Harmon T, Burkhart G, Applebaum H. Perforated pseudomembranous colitis in the breast-fed infant. J Pediatr Surg. 1992;27:744–6. DOI:
  6. Cahill JB Jr, Bailey EM, Chien S, et al. Levofloxacin secretion in breast milk: A case report. Pharmacotherapy. 2005;25:116–8. DOI:
  7. Sorensen HT, Skriver MV, Pedersen L et al. Risk of infantile hypertrophic pyloric stenosis after maternal postnatal use of macrolides. Scand J Infect Dis. 2003;35:104-6. DOI:
  8. Stang H. Pyloric stenosis associated with erythromycin ingested through breast milk. Minn Med. 1986;69:669-70, 82.
  9. Abdellatif M, Ghozy S, Kamel MG et al. Association between exposure to macrolides and the development of infantile hypertrophic pyloric stenosis: a systematic review and meta-analysis. Eur J Pediatr. 2019;178:301-14. DOI:
  10. Almaramhy HH, Al-Zalabani AH. The association of prenatal and postnatal macrolide exposure with subsequent development of infantile hypertrophic pyloric stenosis: A systematic review and meta-analysis. Ital J Pediatr. 2019;45:20. DOI: